Illustration of the analytical description of the spot transit proposed in this paper. The top panel shows the model for the single-spot case. The model is shown in the time domain on the left, and in the Fourier domain on the right. Each time, the distinction is made between the single-transit-spot/peakless case (orange) and the multiple-transit-spot/with peaks case (blue). The bottom of the figure illustrates the general case with both multiple-transit and single-transit spots’ contributions.